Ignition timer



March 9, 1954- M. ca. BALES IGNITION TIMER 2 Sheets-Sheet 1 Filed April 9. 1949 March 9, 1954 BALES 2,671,829

IGNITION TIMER Filed April 9. 1949 2 Sheets-Sheet 2 //v VE'A/TOB Patented Mar. 9, 1954 UNITED STATES PATENT OFFICE IGNITION TIMER Max G. Bales, Anderson, Ind., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application April 9, 1949, Serial No. 86,422

9 Claims. (Cl. 200-31) This invention relates to ignition timers comprising a cam operated circuit breaker attached to a plate transverse to the cam axis and rotatably supported directly by the timer housing in a manner such that the axis of rotation of the plate will coincide with the axis of rotation of the cam. The patent to J. L. Arthur, No. 2,125,368, issued August 2, 1938, discloses an ignition timer of this type. The housing of the timer has an annular groove providing a ball race which receives balls also received by ears or inner race members connected with the movable circuit breaker plate. It has been found that after continual operation of the timer over a long period, the outer ball race, which is provided by the cast iron housing, becomes indented so that the balls do not roll as freely as they did originally. This interferes with freedom of rotation of the breaker plate and with the proper functioning of a device responsive to engine intake suction for rotating the breaker plate.

An object of the invention is to provide for "the servicing of timers of the type shown in'the Arthur patent, This is accomplished by a replacement breaker plate and three bearing mem bers preferably made of molded plastic and adapted to be retained in fixed positions by the housing and adapted to be engaged by cars connected with the breaker'plate.

Further objects and advantages of the present'invention will be apparent from the following description, reference being had to the ac- 'companying drawings wherein a preferred'em- :bodiment of the present invention is clearly shown. In the drawings: .Fig. 1 is aplan view of an ignition timer of the type disclosed in the Arthur patent retaken on the line 5-5 of Fig. 3.

Figs. 6 to 11 are diagrams showing the steps of assembling the replacement bearing members.

--Fig. 12 is a fragmentary sectional view showing how bearing members similar to those shown in. Figs. 3 to 11 canbe used as parts of new isnitiontimers, r

Referring to Figs. 1 and 2, which show the old construction, a housing 20 supports an engine driven shaft 2! which drives a timer cam 22 through a device 23 which, in response to change in engine speed, varies the angular relation between the cam 22 and the shaft 2|. Cam 22 (Fig. 1) engages a rubbing block 24 carried by a lever 25 pivoted on a stud 26 attached to a bracket 21 attached to a circuit breaker plate 36 and carrying a fixed contact 28 engageable with a movable contact 29 carried by lever 25. A leaf spring 30 urges the lever 25 in a counterclockwise direction to cause the contacts to be normally engaged and to resist separation thereof when a lobe of the cam 22 engages the rubbing block 24. Plate 3| is supported for rotation coaxially with the axis of the cam 22 by three balls 32 which are received by an annular groove 33 provided by the housing 20 coaxial with the axis of the cam 22 and received by ball races provided respectively by two relatively rigid ears 34 integral with the plate 3| and by a relatively resilient ear 36 attached to plate 3| by a tubular rivet 31. Each ear has two lugs 35 between which the balls 32 are located. The resilient ear 36 urges its ball 32 toward the housing and causes the ears 34 to press their retained balls toward the housing. The housing 20 is provided with grooves 38 extending from the top face of the housing down through the groove 33. When the plate 3! is so located that the ears 34 are adjacent the grooves 38, the balls 32 can be inserted. 5

Screws 39 attach to housing 20 a bracket 4 supporting a suction device comprising'shells 4| and 42 which are secured together at their peripheries with the edge of a diaphragm 43 between. A rivet 44 connects the central portion of the diaphragm 53 with an arm'45which a screw 46 pivotally connects with the rivet 31 attached to plate 3|, as shown in Fig. 2. The rivet 44 receives one end of a compression spring 41, the other end of which bears against a pipe coupling 43 threaded into a bushing 49 attached to the shell 42. The threaded opening '50 in the coupling 48 provides for connection with a pipe connected with the engine intake manifold. Obviously, increase of engine suction will effect clockwise rotation of the ignition timer to effect spark advance, it being understood that the cam 22 rotates counterclockwise.

A screw 5! attaches to the plate 3| a bracket 52 attached to the metal case of a condenser 53,.one foil of which is grounded on the case and the other of which is connected by a wire 54 with the fixed end of the spring 30 and with a wire 55 connected with a terminal 56 insulatingly supported by the housing 26.

The cam 22 is connected with a distributor rotor 60 having a spring blade 6| carrying a central contact 62 engaging a button 63 supported by a metal terminal socket 64 anchored centrally in a distributor cap 65 of molded insulating material which providesa cover for the housing 20 on which it is retained in the conventional manner. Cap 65 provides a circular row of terminal sockets 66, each adapted to make connection with a spark plug cable and each having a post Glpast which there rotates a metal segment '68 supported by the rotor 60 and'connectccl with the spring blade 6|.

'Io service a timer of the type shown in Figs. 1 and 2, the cap 65 is removed from 'the housing 20, the wire 55 disconnected from the terminal 56 and the lever 45 is freed from connection with ;theplate 3| by removing the screw 46. Terminal 56 is removed to; permit removal of plate 3 I. Then yby turning the plate 31 so that the balls 32 can ears ll and i3 integral therewith anda relatively resilient car 12 connected to plate by a tubular rivet'31. The notched base of ear straddles a small circular boss 12a extruded from plate Boss 12a and the rivet 3i fix the location of the ear 12 relative to the plate car '53 is shown in Fig.5; andear ii is like car '53. The

resilient ear (2 is similar to cars Stand '53 but is thinner. The ears H, 12 and i3 engage, respectively, threebearing members ti, and shown in solid black in Fig. 3. Each of the bearing members, for example 83 in Fig. 5, has an arcuate boss8-ll of torical cross sectional contour adapted to be received by the groove of the timer housing and has at right angles to the boss 34, a boss 85 adapted to be received by a groove The boss: 85fixes the bearing member in a definite position along the groove 33. The inner face of each, bearing member is shaped as shown best in Fig. 5, so that it will be engaged by an ear of the plate Hlattwo places marked and 37. The resilient ear [2, by pressing against the adjacent bearing member 82, urges the ears 'ii and 13 against the bearing members 31 and respectively. These bearing members present very smooth surfaces in contact with the ears of the breaker plate; and these surfaces are all coaxial with the axis of the timer cam. When these surfaces are greased, the frictional resistance between the bearings and the ears of the breaker plate is so low that there is practically no inter ference with the operation of the suction device to effect ignition timing "in accordance with the lo'a'don the engine. Obviously, when these re placem'entbearings have become worn, they can be replaced by new ones.

Figs. 6l1 illustrate the procedure of assembling the bearing members. Bearing 8! is assembled as shown in Fig. 6. Plate'iii is rotated counterclockwise to cause itsear H to engage the bearing 81, as shown in Figs. 7' and 8. Bearing '82. is assembled as shown in Fig. 8 and plate is'rotated clockwise to cause ear F2 to engage bearing BZ'as shown in Fig. 9. Bearing 33 is as sembled as shown in Fig. 10. While prying the plate 16in about the direction indicated by arrow ill in Fig. 11 by means of a screwdriver blade :9'0'inserted between the housing 2?) and the car 73 in order to cause that ear'to clear the bearing housing 20. Lever 45 is pivotally connected with is'connected with said terminal.

the new plate 10 by screw 46 received by a tapped hole in rivet 31'. The old terminal is reassembled with the housing 20' and the new wire 55 Thus the timer is serviced by a new circuit breaker and plate assembly and three new bearings.

The present invention is not limited in its application merely to the servicing of ignition timers in use but may be applied to new equipment.

The timer housing, a fragment of which is shown at 20 in Fig. 12, is prbvided with three radially extending'holes ZO 'h, the center lines of which are in a plane at right angles to the axis of rotation of the timer cam. Each hole Z-flh. receives the shank [ills of a bearing member if)! of suitable material, there being three of these bearing members shaped as shown in Fig. 5, except for the omission of bosses 84 and 85. Whe'n'bearing's is! become worn, they are easily replaced by new ones. I

From the foregoing description, it is apparent that the present invention contemplates the'combination with a housing 20 or 20 having a'n inner cylindrical wall coaxial with the timer cam of three bearing members BI, 82, 83 (Figs. 3-41) or threemembers l0] (Fig. 12) of suitable bearing material having concentric inner and outer surfaces, the outer surfaces conforming to the inner cylindrical surface of the housing whenretained in assembly therewith by the ears of the circuit breaker plate 10, and the inner surfaces being coaxial with respect to the housing inner wall and to the cam. Recesses provided by the housing, such as annular groove 33 and straight grooves38 (Figs. 3-11) receive bossparts 84, 85

of bearing members 8'l, 82, B3 and holesor cylindrical recesses 20'h'in housing 20' (Fig, 12) receive cylindrical parts or shanks lllls of bearing members I0 I, for the purpose of fixing-these bearing members longitudinally and circumferentially with respect to the-inner cylindrical wall of housings 20 or 20. The shanks l0ls of bearing'members l0] cannot rotate in holes Zllh because-the outer cylindrical surfaces of the members Hill are pressed against'theinner cylindrical wall of the housing.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. An ignition timer comprising ahousin'g having a cylindrical inner wall, a timer cam supported'by'the housing coaxially with the'wall, three arcuate-shaped non-metallic bearing" members: having concentric concave inner and convex outer surfaces, the outer'surfaces fashioned-to bear against inner cylindrical surface of the housing walls when the bearing members are assembled with the housing and the inner surfaces being coaxial with respect to the cam, recesses providedbythe housing and parts provided by the bearing members for reception by the recesses whereby the members are fixed longitudinally and circumferentially relative to the housing wall, a platehaving earsprovided with surfaces concentric with the housing walls'and 's'haped to ride on the inner surfaces of the bearing members, at least one of the ears being relatively resilient so that when the plate is in operative position with the said bearing member that the bearing members are held in place solely by the pressure of the ears thereon, said ears locating the plate in a plane at right angles to the cam axis and cooperating with the bearing members to provide for facile rotation of the plate relative to the housing, and a circuit breaker supported by the plate for operation by the cam.

2. An ignition timer according to claim 1 in which the housing has an annular groove within its cylindrical wall in a plane at right angles to the cam axis and three recesses extending from an end surface of the housing across the cylindrical wall to the groove and in which each bearing member has an annular boss part received by the groove and another boss part received by a recess of the housing wall.

3. An ignition timer according to claim 1 in which the housing has three cylindrical recesses extending from the housing wall and radially from the axis of the housing wall, the center line of the recesses being in a plane at right angles to the housing wall axis, and in which each bearing member has a cylindrical part received by a cylindrical recess in the housing wall, said recesses and parts cooperating to fix the bearing longitudinally and circumferentially relative to the housing wall and said housing inner wall and the outer surfaces of the bearing members cooperating to prevent rotation of the members axially of the cylindrical recesses of the housing.

4. A distributor assembly comprising in combination, a body having a circumferential groove thereabout and a plurality of vertically disposed equally spaced slots intersecting said groove; a plurality of arcuate shaped bearing members, one of which is provided for each slot, each of said bearing members including a bearing surface on the concave side thereof and an arcuate bulge on the convex side thereof fashioned to fit within said groove and hold the member against vertical movement in said body, each member also including a vertically disposed bulge at the convex side thereof adapted to fit with said slot for holding the member against rotational movement in said body; a breaker plate; a plurality of shoes equal in number to said members associated with said plate and shaped to slide on the bearing surfaces of said members, at least one of said shoes having a degree of springiness so that when the plate. is in operative position with said members the bearing members are held in place solely by the pressure of the shoes thereon.

5. A distributor comprising in combination, two members rotatable relative to one another consisting of a body and a breaker plate positioned therein, a plurality of antifriction bearings disposed between said members, each of said bearings having a portion detachably anchored to one of said members for preventing relative movement in the said one member; and a bearing groove for said bearings, said groove being carried by the other of said members, whereby the breaker plate is freely rotatable relative to the body on said bearings.

A distributor comprising in combination, a housing; a plurality of circumferentially spaced elongated non-metallic antifriction bearing elements each of said elements having a portion anchored to the housing to prevent relative movement in the said housing; a circuit breaker plate mounted within the housing; a plurality of spaced ears associated with the plate, each of said ears having a groove formed to at least partially fit around the elements whereby the plate is freely rotatable with respect to the housing without wobble.

7. A distributor comprising in combination, two members rotatable relative to one another consisting oi a housing and a breaker plate positioned therein; a plurality of circumferentially spaced elongated non-metallic antifriction surfaces having a curvature similar to the curvature of said housing, each of said bearings having a boss thereon and engaging an axially extending groove in one of said members; and a bearing groove for said bearings, said groove being carried by the other of said members, whereby the breaker plate is rotatable relative to the body on said bearings.

8. A distributor comprising in combination, a housing; a plurality of spaced non-metallic antifriction bearing elements, each of said elements having a boss thereon fitting a vertically disposed groove in said housing to form an anchor for said element; a circuit breaker plate mounted with the housing; a plurality of spaced ears carried by the plate, each of said ears having a groove formed to slide on the bearing elements, whereby the circuit breaker plate is freely rotatable with respect to the housing.

9. A distributor comprising in combination; a housing having a plurality of arcuate-shaped non-metallic bearing members, each of said elements having anchoring engagement with said housing to prevent axial and rotational movements in said housing; a circuit breaker plate mounted in said housing; a plurality of spaced ears, each of said ears having formations for engaging the bearing members to slide on the bearing members whereby the circuit breaker plate is rotatable relative to the housing on said bearing members.

MAX G. BALES.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,075,904 Lang Apr. 6, 1937 2,303,464 Hove Dec. 1, 1942 2,390,050 Bales Dec. 4, 1945 2,444,149 Aldridge June 29, 1948 2,489,775 Haubert Nov. 29, 1949 

